Method of manufacturing electronic tube and electronic tube

Abstract

The present invention has an object to provide a method of manufacturing an electronic tube capable of eliminating deterioration of image quality due to an excessively high electron reflection effect of a material comprising a metal element with an atomic number not lower than 70 and painted on a shadow mask and deterioration of image quality due to spontaneous peeling of a coat on the surface of the shadow mask. A paint mainly comprising a solated metal oxide or a metal alkoxide of an element with an atomic number not lower than 40 is painted to form an electron reflection coat with an amount of coating of less than 2 mg/cm2 so as to achieve coating on an electron gun side surface of a shadow mask.

What is claimed is:  
     
       1. An electronic tube characterizing 
       an electron reflection coat formed on an electron gun side surface of a shadow mask and mainly comprising an element with an atomic number not lower than 40 but not higher than 69.  
     
     
       2. The electronic tube according to claim  1 , wherein the amount of coating is less than 2 mg/cm 2 . 
     
     
       3. An electronic tube characterized in that 
       an electron reflection coat mainly comprising an element with an atomic number not lower than 70 is formed on an electron gun side surface of a shadow mask to an amount of coating of less than 0.2 mg/cm 2 .